Airplanes deploy revers thrusters when landing which are basically just shaped metal shields that move into place behind the engines to provide reverse thrust and slow the plane.
But adding a fan on a sailboat is seen as stupid and doesn’t work.
Airplanes deploy revers thrusters when landing which are basically just shaped metal shields that move into place behind the engines to provide reverse thrust and slow the plane.
But adding a fan on a sailboat is seen as stupid and doesn’t work.
No fan of any size will ever push the sail on the boat it’s mounted to; that’s not how physics works.
You might want to check your physics because that’s pretty much exactly how a propeller works …
Show me one airboat with a sail on it, you dunce.
The thing about air boats is that they don’t need sails.
BECAUSE BLOWING A SAIL WITH A FAN DOESN’T WORK.
But it does. It just works even better without the sail.
It can be, as long as the sail is set up in such a way that incoming air is deflected backwards to some degree rather than at a right angle to the fan (such as with a curved sail). Consider a still boat in still air (thus with no net acceleration in any direction to start). You push some air forwards towards the sail, then the sail deflects that stream of air outwards and slightly backwards. This means the combined fan-sail system (the ship taken as a whole) is taking in initially still air, and that air ends up with a net momentum backwards, so there must be push forwards. This is very inefficient compared to doing away with the sail and pointing the fan the other way, so theres no reason to do it in practice, but it doesn’t violate conservation of momentum or anything because the ship isn’t a closed system.
So you have never seen an airboat?
https://en.wikipedia.org/wiki/Airboat
Have you ever seen an airboat with a sail?